HomeGrid - Configuring Stack'd Series In/Out of Parallel

Note: This guide explains how to properly configure multiple HomeGrid Stack’d Series systems to run in parallel. This guide assumes that the all of the electrical wiring has been completed. Following these steps ensures that the systems work together efficiently and avoid errors.

TABLE OF CONTENTS

1. Pre-Configuration Checklist
2. Putting Stacks Into Parallel
3. Taking Stacks out of Parallel

Pre-Configuration Checklist

Important: Before configuring systems in or out of parallel, ensure the following steps are completed:

1. Battery Modules

• Ensure all battery modules are the same size (capacity). For proper parallel operation, every stack must have the same number of modules.
  
  

2. Check Firmware

Note: Refer to the Generation Guide to determine your system's generation.

For Generation 3 BMS Controller:

1. Set the ‘INV SET’ dipswitches temporarily to: ( ON | OFF | ON | ON | ON | ON )
   
   
2. Watch the firmware versions (VER S.) on the controller. Anything older than the following needs to be updated:
   • BMS Board: 100 - 02009
   • Display Board: 101 - 01098
   • BMS Main Control Board 102 - 04007
   • Battery Module:
     • Gen 3: 03044
     • Gen 2: 02056    
       
       
       
3. Reset the ‘INV SET’ dipswitches to their original position. No power cycling required.
   
   

For Generation 2 BMS Controller (no Wi-Fi antenna port, external Skybox):

1. Power cycle the BMS and watch for the firmware version during startup.
   • The BMS will go through a sequence of 4 different versions upon startup, with the 4th screen being the Important Firmware Version.
     
     
     
2. Only the controller firmware (The most recent version being 40007) will be identified.

3. Clear Errors

• Ensure no errors are present on the BMS displays. If errors exist, resolve them before continuing.

Putting Stacks Into Parallel

This aspect of the guide is used to put systems into parallel. 

1. System Isolation

• Each BMS must be turned off, and all stacks should be isolated from one another.
  1. Press the power button OFF, located on the BMS (near the LCD display).

Note: The battery modules do not need to be turned off during this process, just the BMS.

2. Set Up the DIP Switches

1. Master BMS (Stack 1)

   • Set the 'INV Set' DIP switches to Parallel Detection Mode: ( OFF | ON | ON | ON | ON | ON ) 

   • Set the ‘ADDR Set’ DIP switches to identify as unit 1: ( ON | OFF | OFF | OFF | OFF | OFF )

   • Set the 'IMPD Set' DIP switches to ( OFF | OFF | OFF | OFF | OFF | ON )

2. Additional Stacks (Stack 2, Stack 3, etc.)

   • Set the 'INV Set' DIP switches to ( ON | OFF | OFF | OFF | OFF | OFF )

   • For each additional stack, set the ‘ADDR Set’ DIP switches as follows:
     
     

     
     

   • Set the 'IMPD Set' DIP Switches to ( OFF | OFF | OFF | OFF | OFF | ON )

3. Link Parallel Stacks with Communication Cables

1. Use Ethernet Cables to connect the stacks:
   • Start by connecting the ‘Link A’ port on the master BMS (Stack 1) to the ‘Link B’ port on the second stack.
   • Continue linking the remaining stacks using the same method: ‘Link A’ to ‘Link B’ between each stack.
     
     
2. Ensure all communication cables are firmly connected to avoid interruptions during parallel operation.

4. Power On Sequence

1. Turn on each stack in order, starting from last Stack in the paralleling sequence:
   • Press the power button ON for each stack.
   • Wait 30 seconds between turning on each stack to ensure proper initialization.
     
     
2. Turn On the Master Stack Last: 
   • Once all other stacks are powered on, turn on the master BMS.

5. Verify Parallel Configuration

1. After all stacks are powered on, the master BMS will display the total number of stacks detected.
   • It may take up to 3 minutes for the master BMS to detect all parallel systems.
     
     
2. Check the BMS Display on the master stack to confirm the correct number of detected systems.
   • If the number of detected systems is incorrect, double-check the DIP switch settings and power connections.
     
     

During Parallel Detection Mode, the display should show a code ‘62’ at the top of the screen. The number in the center indicates how many stacks the master BMS has detected. The reference in the example below is currently detecting 2 Stacks.

6. Set Dipswitches for Operation

1. After configuring the system in parallel, only the ‘INV Set’ DIP switch on the master BMS needs to be adjusted. 
   • Set the 'INV Set' DIP Switches to match the correct operation mode (Inverter/Open Loop)
     
     
     
     
2. Once this setting is applied, all stacks should be in parallel and display their normal operation screens (SOC, SOH, Voltage, etc.).
   
   

Note: No DIP Switches on any follower stacks need to be altered as only the master BMS does any communication with the inverter.

Warning: If any errors are displayed during or after configuration, please contact HomeGrid Support for assistance.

Taking Stacks Out of Parallel

This aspect of the guide is used to take systems out of parallel, which can be helpful when needing to perform a firmware update or when needing to isolate a battery stack for another reason.

1. Power Off BMS Units

• Each BMS must be turned off
  1. Press the power button OFF, located on the BMS (near the LCD display).

Note: The battery modules do not need to be turned off during this process, just the BMS.

2. Set Up the DIP Switches

We are changing each system to identify as an isolated stack. Therefore we will set each one the same way we would set a master stack.

1. Please set the dipswitches on each stack to the below:

   • Set the 'INV Set' DIP switches to Parallel Detection Mode: ( OFF | ON | ON | ON | ON | ON ) 

   • Set the ‘ADDR Set’ DIP switches to identify as unit 1: ( ON | OFF | OFF | OFF | OFF | OFF )

   • Set the 'IMPD Set' DIP switches to ( OFF | OFF | OFF | OFF | OFF | ON )

3. Isolate Each Stack

• Disconnect the Ethernet cables that link the stacks together to prevent communication between them.
  
  
• You only need to remove one end of each cable to break the connection between stacks.

4. Power On BMS Units

1. Turn on each stack, the order does not matter as the stacks are no longer connected:
   • Press the power button ON for each stack.

5. Verify Isolated Configuration

1. After all stacks are powered on, each BMS will display the total number of stacks detected.
   • It may take up to 3 minutes for each BMS to detect itself as a stand-alone system.
     • If everything was done correctly, you will eventually see a 62 and a 1 on the display
       
       
   • During Parallel Detection Mode, the display should show a code ‘62’ at the top of the screen. The number in the center indicates how many stacks the master BMS has detected. The reference in the example below is currently detecting 1 Stack.
   
   
   
2. Once the BMS is detecting only 1 stack, wait 30 seconds before changing any DIP switches to allow the BMS properly adjust to the change.
   
   
3. After configuring the system out of parallel, only the ‘INV Set’ DIP switch on each BMS needs to be adjusted. 
   • Set the 'INV Set' DIP Switches to Open Loop Configuration temporarily: ( ON | OFF | OFF | OFF | OFF | OFF )

The stacks are now out of parallel. To put them pack into parallel, please refer to Part 2: Putting Stacks Into Parallel.

For assistance, contact HomeGrid Support at +1 725-373-5350 (Weekdays 6 AM - 4 PM PST) or email support@lithionbattery.com.